This invention relates to vehicles powered by air propellers and more particularly to an improved induction system for the driving engine of the propeller.
A wide variety of vehicles, both land, water and air are driven by air propellers. The propeller is driven by an associated engine and the engine is normally placed in close proximity to the propeller. With many of these types of vehicles, such as those generally referred to as swamp buggies that operate on the water, the engine is relatively exposed and thus the air flow created by the propeller passes across the engine. Although this has certain advantages, it presents a number of problems in the design of the engine components, such as its induction system.
A first of the problems with designing the induction system for a vehicle of this type is that the carburetor normally has its fuel bowl vented to atmospheric pressure so as to balance the amount of the fuel discharged to the engine in response to the difference between atmospheric pressure and induction system pressure. However, if the carburetor is placed downstream of the propeller and is located in its wash or if it is upstream, the fuel bowl vent will be subjected to a pressure other than atmospheric due to the airflow caused by the propeller. As a result, there can be improper amount of fuel delivered to the engine, either too much if the location is in a high pressure area, or too low if the vent is in a low pressure area.
It is, therefore, a principle object of the this invention to provide an improved arrangement for controlling the air pressure delivered to a charge former of an internal combustion engine of an air propeller powered vehicle.
It is a further object of this invention to provide an improved fuel bowl venting arrangement for a carburetor having such an application.
In addition to the difficulties providing the proper pressure for the fuel bowl venting, the intake device for the air induction system of the engine also presents problems with this type of vehicle. Like the fuel bowl vent, if the induction system air inlet is disposed either downstream of the propeller in its wash, or upstream on its intake side, the airflow generated by the propeller can adversely affect the performance of the engine. Furthermore, the changes in airflow with engine speed can give rise to calibration problems. Although this problem could be avoided by providing a remote air inlet location, such remote inlet locations cause pressure losses that can diminish the performance of the engine.
It is, therefore, a still further object of this invention to provide an improved air induction system for the intake of an engine driving an air propeller powered vehicle.
It is a further object of this invention to provide an improved air intake device for a propeller driven vehicle.